Related KB Article
Windows Server 2012 R2
For Windows Server 2008 R2 see below
When initially starting the Web Administration Console, the server returns a 500.19 internal server error.
This is normally caused by not having ASP 4.5 installed
Run the Add Roles and Features Wizard and install the ASP.NET 4.5 role as highlighed in the screenshot below.
After installation restart IIS.
We have seen a similar issue to this however the 500.19 Error page contains a blank config section. If this is the case it can be resolved by reinstalling the URL Rewrite Module.
Windows Server 2008 R2
This is caused by installing .NET before installing IIS. IIS hasn't registered .NET because of the order of installation.
Run C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -i